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Message-Id: <20190115215651.9448-11-jeffrey.t.kirsher@intel.com>
Date: Tue, 15 Jan 2019 13:56:46 -0800
From: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To: davem@...emloft.net
Cc: Brett Creeley <brett.creeley@...el.com>, netdev@...r.kernel.org,
nhorman@...hat.com, sassmann@...hat.com,
Anirudh Venkataramanan <anirudh.venkataramanan@...el.com>,
Andrew Bowers <andrewx.bowers@...el.com>,
Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next 10/15] ice: Add support for adaptive interrupt moderation
From: Brett Creeley <brett.creeley@...el.com>
Currently the driver does not support adaptive/dynamic interrupt
moderation. This patch adds support for this. Also, adaptive/dynamic
interrupt moderation is turned on by default upon driver load.
In order to support adaptive interrupt moderation, two functions were
added, ice_update_itr() and ice_itr_divisor(). These are used to
determine the current packet load and to determine a divisor based
on link speed respectively.
This patch also adds the ICE_ITR_GRAN_S define that is used in the
hot-path when setting a new ITR value. The shift is used to pet two
birds with one hand, set the ITR value while re-enabling the
interrupt. Also, the ICE_ITR_GRAN_S is defined as 1 because the device
has a ITR granularity of 2usecs.
Signed-off-by: Brett Creeley <brett.creeley@...el.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@...el.com>
Tested-by: Andrew Bowers <andrewx.bowers@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---
.../net/ethernet/intel/ice/ice_hw_autogen.h | 1 +
drivers/net/ethernet/intel/ice/ice_lib.c | 24 +++++--
drivers/net/ethernet/intel/ice/ice_main.c | 23 +++++--
drivers/net/ethernet/intel/ice/ice_txrx.c | 65 ++++++++++++++++++-
drivers/net/ethernet/intel/ice/ice_txrx.h | 30 +++++----
5 files changed, 120 insertions(+), 23 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice_hw_autogen.h b/drivers/net/ethernet/intel/ice/ice_hw_autogen.h
index 5507928c8fbe..f9a38f2cd470 100644
--- a/drivers/net/ethernet/intel/ice/ice_hw_autogen.h
+++ b/drivers/net/ethernet/intel/ice/ice_hw_autogen.h
@@ -110,6 +110,7 @@
#define GLINT_DYN_CTL_CLEARPBA_M BIT(1)
#define GLINT_DYN_CTL_SWINT_TRIG_M BIT(2)
#define GLINT_DYN_CTL_ITR_INDX_S 3
+#define GLINT_DYN_CTL_INTERVAL_S 5
#define GLINT_DYN_CTL_SW_ITR_INDX_M ICE_M(0x3, 25)
#define GLINT_DYN_CTL_INTENA_MSK_M BIT(31)
#define GLINT_ITR(_i, _INT) (0x00154000 + ((_i) * 8192 + (_INT) * 4))
diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index a1f523a9d39d..27c3760ae5cb 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -1717,22 +1717,34 @@ static u32 ice_intrl_usec_to_reg(u8 intrl, u8 gran)
static void
ice_cfg_itr(struct ice_hw *hw, struct ice_q_vector *q_vector, u16 vector)
{
- u8 itr_gran = hw->itr_gran;
-
if (q_vector->num_ring_rx) {
struct ice_ring_container *rc = &q_vector->rx;
- rc->itr = ITR_TO_REG(ICE_DFLT_RX_ITR, itr_gran);
+ /* if this value is set then don't overwrite with default */
+ if (!rc->itr_setting)
+ rc->itr_setting = ICE_DFLT_RX_ITR;
+
+ rc->target_itr = ITR_TO_REG(rc->itr_setting);
+ rc->next_update = jiffies + 1;
+ rc->current_itr = rc->target_itr;
rc->latency_range = ICE_LOW_LATENCY;
- wr32(hw, GLINT_ITR(rc->itr_idx, vector), rc->itr);
+ wr32(hw, GLINT_ITR(rc->itr_idx, vector),
+ ITR_REG_ALIGN(rc->current_itr) >> ICE_ITR_GRAN_S);
}
if (q_vector->num_ring_tx) {
struct ice_ring_container *rc = &q_vector->tx;
- rc->itr = ITR_TO_REG(ICE_DFLT_TX_ITR, itr_gran);
+ /* if this value is set then don't overwrite with default */
+ if (!rc->itr_setting)
+ rc->itr_setting = ICE_DFLT_TX_ITR;
+
+ rc->target_itr = ITR_TO_REG(rc->itr_setting);
+ rc->next_update = jiffies + 1;
+ rc->current_itr = rc->target_itr;
rc->latency_range = ICE_LOW_LATENCY;
- wr32(hw, GLINT_ITR(rc->itr_idx, vector), rc->itr);
+ wr32(hw, GLINT_ITR(rc->itr_idx, vector),
+ ITR_REG_ALIGN(rc->current_itr) >> ICE_ITR_GRAN_S);
}
}
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 093708b5c0ef..e59f8b29af49 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -1389,7 +1389,6 @@ static int ice_req_irq_msix_misc(struct ice_pf *pf)
{
struct ice_hw *hw = &pf->hw;
int oicr_idx, err = 0;
- u8 itr_gran;
u32 val;
if (!pf->int_name[0])
@@ -1453,10 +1452,8 @@ static int ice_req_irq_msix_misc(struct ice_pf *pf)
PFINT_MBX_CTL_CAUSE_ENA_M);
wr32(hw, PFINT_MBX_CTL, val);
- itr_gran = hw->itr_gran;
-
wr32(hw, GLINT_ITR(ICE_RX_ITR, pf->hw_oicr_idx),
- ITR_TO_REG(ICE_ITR_8K, itr_gran));
+ ITR_REG_ALIGN(ICE_ITR_8K) >> ICE_ITR_GRAN_S);
ice_flush(hw);
ice_irq_dynamic_ena(hw, NULL, NULL);
@@ -1997,6 +1994,23 @@ static int ice_init_interrupt_scheme(struct ice_pf *pf)
return 0;
}
+/**
+ * ice_verify_itr_gran - verify driver's assumption of ITR granularity
+ * @pf: pointer to the PF structure
+ *
+ * There is no error returned here because the driver will be able to handle a
+ * different ITR granularity, but interrupt moderation will not be accurate if
+ * the driver's assumptions are not verified. This assumption is made so we can
+ * use constants in the hot path instead of accessing structure members.
+ */
+static void ice_verify_itr_gran(struct ice_pf *pf)
+{
+ if (pf->hw.itr_gran != (ICE_ITR_GRAN_S << 1))
+ dev_warn(&pf->pdev->dev,
+ "%d ITR granularity assumption is invalid, actual ITR granularity is %d. Interrupt moderation will be inaccurate!\n",
+ (ICE_ITR_GRAN_S << 1), pf->hw.itr_gran);
+}
+
/**
* ice_verify_cacheline_size - verify driver's assumption of 64 Byte cache lines
* @pf: pointer to the PF structure
@@ -2163,6 +2177,7 @@ static int ice_probe(struct pci_dev *pdev,
mod_timer(&pf->serv_tmr, round_jiffies(jiffies + pf->serv_tmr_period));
ice_verify_cacheline_size(pf);
+ ice_verify_itr_gran(pf);
return 0;
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 49fc38094185..384ac5c82e00 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -1052,6 +1052,69 @@ static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
return failure ? budget : (int)total_rx_pkts;
}
+/**
+ * ice_buildreg_itr - build value for writing to the GLINT_DYN_CTL register
+ * @itr_idx: interrupt throttling index
+ * @reg_itr: interrupt throttling value adjusted based on ITR granularity
+ */
+static u32 ice_buildreg_itr(int itr_idx, u16 reg_itr)
+{
+ return GLINT_DYN_CTL_INTENA_M | GLINT_DYN_CTL_CLEARPBA_M |
+ (itr_idx << GLINT_DYN_CTL_ITR_INDX_S) |
+ (reg_itr << GLINT_DYN_CTL_INTERVAL_S);
+}
+
+/**
+ * ice_update_ena_itr - Update ITR and re-enable MSIX interrupt
+ * @vsi: the VSI associated with the q_vector
+ * @q_vector: q_vector for which ITR is being updated and interrupt enabled
+ */
+static void
+ice_update_ena_itr(struct ice_vsi *vsi, struct ice_q_vector *q_vector)
+{
+ struct ice_hw *hw = &vsi->back->hw;
+ struct ice_ring_container *rc;
+ u32 itr_val;
+
+ /* This block of logic allows us to get away with only updating
+ * one ITR value with each interrupt. The idea is to perform a
+ * pseudo-lazy update with the following criteria.
+ *
+ * 1. Rx is given higher priority than Tx if both are in same state
+ * 2. If we must reduce an ITR that is given highest priority.
+ * 3. We then give priority to increasing ITR based on amount.
+ */
+ if (q_vector->rx.target_itr < q_vector->rx.current_itr) {
+ rc = &q_vector->rx;
+ /* Rx ITR needs to be reduced, this is highest priority */
+ itr_val = ice_buildreg_itr(rc->itr_idx, rc->target_itr);
+ rc->current_itr = rc->target_itr;
+ } else if ((q_vector->tx.target_itr < q_vector->tx.current_itr) ||
+ ((q_vector->rx.target_itr - q_vector->rx.current_itr) <
+ (q_vector->tx.target_itr - q_vector->tx.current_itr))) {
+ rc = &q_vector->tx;
+ /* Tx ITR needs to be reduced, this is second priority
+ * Tx ITR needs to be increased more than Rx, fourth priority
+ */
+ itr_val = ice_buildreg_itr(rc->itr_idx, rc->target_itr);
+ rc->current_itr = rc->target_itr;
+ } else if (q_vector->rx.current_itr != q_vector->rx.target_itr) {
+ rc = &q_vector->rx;
+ /* Rx ITR needs to be increased, third priority */
+ itr_val = ice_buildreg_itr(rc->itr_idx, rc->target_itr);
+ rc->current_itr = rc->target_itr;
+ } else {
+ /* Still have to re-enable the interrupts */
+ itr_val = ice_buildreg_itr(ICE_ITR_NONE, 0);
+ }
+
+ if (!test_bit(__ICE_DOWN, vsi->state)) {
+ int vector = vsi->hw_base_vector + q_vector->v_idx;
+
+ wr32(hw, GLINT_DYN_CTL(vector), itr_val);
+ }
+}
+
/**
* ice_napi_poll - NAPI polling Rx/Tx cleanup routine
* @napi: napi struct with our devices info in it
@@ -1108,7 +1171,7 @@ int ice_napi_poll(struct napi_struct *napi, int budget)
*/
if (likely(napi_complete_done(napi, work_done)))
if (test_bit(ICE_FLAG_MSIX_ENA, pf->flags))
- ice_irq_dynamic_ena(&vsi->back->hw, vsi, q_vector);
+ ice_update_ena_itr(vsi, q_vector);
return min(work_done, budget - 1);
}
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h
index 75d0eaf6c9dd..aa646002d653 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.h
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.h
@@ -116,16 +116,15 @@ enum ice_rx_dtype {
/* indices into GLINT_ITR registers */
#define ICE_RX_ITR ICE_IDX_ITR0
#define ICE_TX_ITR ICE_IDX_ITR1
-#define ICE_ITR_DYNAMIC 0x8000 /* use top bit as a flag */
-#define ICE_ITR_8K 125
+#define ICE_ITR_8K 124
#define ICE_ITR_20K 50
-#define ICE_DFLT_TX_ITR ICE_ITR_20K
-#define ICE_DFLT_RX_ITR ICE_ITR_20K
-/* apply ITR granularity translation to program the register. itr_gran is either
- * 2 or 4 usecs so we need to divide by 2 first then shift by that value
- */
-#define ITR_TO_REG(val, itr_gran) (((val) & ~ICE_ITR_DYNAMIC) >> \
- ((itr_gran) / 2))
+#define ICE_DFLT_TX_ITR (ICE_ITR_20K | ICE_ITR_DYNAMIC)
+#define ICE_DFLT_RX_ITR (ICE_ITR_20K | ICE_ITR_DYNAMIC)
+#define ICE_ITR_DYNAMIC 0x8000 /* used as flag for itr_setting */
+#define ITR_TO_REG(setting) ((setting) & ~ICE_ITR_DYNAMIC)
+#define ICE_ITR_GRAN_S 1 /* Assume ITR granularity is 2us */
+#define ICE_ITR_MASK 0x1FFE /* ITR register value alignment mask */
+#define ITR_REG_ALIGN(setting) __ALIGN_MASK(setting, ~ICE_ITR_MASK)
#define ICE_DFLT_INTRL 0
@@ -180,13 +179,20 @@ enum ice_latency_range {
};
struct ice_ring_container {
- /* array of pointers to rings */
+ /* head of linked-list of rings */
struct ice_ring *ring;
+ unsigned long next_update; /* jiffies value of next queue update */
unsigned int total_bytes; /* total bytes processed this int */
unsigned int total_pkts; /* total packets processed this int */
enum ice_latency_range latency_range;
- int itr_idx; /* index in the interrupt vector */
- u16 itr;
+ int itr_idx; /* index in the interrupt vector */
+ u16 target_itr; /* value in usecs divided by the hw->itr_gran */
+ u16 current_itr; /* value in usecs divided by the hw->itr_gran */
+ /* high bit set means dynamic ITR, rest is used to store user
+ * readable ITR value in usecs and must be converted before programming
+ * to a register.
+ */
+ u16 itr_setting;
};
/* iterator for handling rings in ring container */
--
2.20.1
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